DESCRIPTION The candidate will study the effects of various glycosaminoglycans (GAG) or proteoglycans (PG) on the expansion of CD34+ cells from human cord blood in vitro. Specifically, various glycosaminoglycans or proteoglycans will be deposited onto tissue culture dishes and screened for their ability to enhance the expansion of human CD34+ cells in in vitro culture. The relative advantages of using immobilized glycans versus their delivery in solution will be determined by total DNA content, cell number, and CD34+ staining among cells after in vitro cultures. Results from these experiments will be used to design a perfusion bioreactor system incorporating the chosen glycans in the synthesis of porous microcarriers. The design and composition of the bioreactor, as well as the operating fluid dynamic parameters, will be optimized in the proposed studies with the goal of producing a high-yield expansion of CD34+ cells.